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Grade 12th passMechanics

if 5 Persons(P1,P2,P3,P4,P5) are standing in a row and the distance between each persons is given(Suppose 1m).At what distance from 1st person an object should be kept so that left side of object forms a team and right side of object forms team and both teams pull the object but it remains in equilibrium.Force of pulling the object by person is F1/d,F2/d,F3/d,F4/d,F5/d respectively.Where d is the distance between person and object. Any idea how to solve?

Profile image of suraj kumar
8 Years agoGrade 12th pass
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1 Answer

Profile image of Askiitians Tutor Team
ApprovedApproved Tutor Answer1 Year ago

To solve the problem of finding the distance from the first person (P1) at which an object should be placed so that it remains in equilibrium while being pulled by two teams formed by the persons on either side, we need to analyze the forces acting on the object. The key here is to ensure that the total pulling force from the left side equals the total pulling force from the right side. Let's break this down step by step.

Understanding the Setup

We have five persons standing in a row, each 1 meter apart:

  • P1 at position 0m
  • P2 at position 1m
  • P3 at position 2m
  • P4 at position 3m
  • P5 at position 4m

Let’s denote the distance from P1 to the object as x. Therefore, the distances from each person to the object will be:

  • P1: d1 = x
  • P2: d2 = x - 1
  • P3: d3 = x - 2
  • P4: d4 = x - 3
  • P5: d5 = x - 4

Calculating Forces

The force exerted by each person on the object is inversely proportional to their distance from it. Thus, the forces can be expressed as:

  • Force by P1: F1 = F1/x
  • Force by P2: F2 = F2/(x - 1)
  • Force by P3: F3 = F3/(x - 2)
  • Force by P4: F4 = F4/(x - 3)
  • Force by P5: F5 = F5/(x - 4)

Setting Up the Equilibrium Condition

For the object to remain in equilibrium, the total force from the left team (P1, P2, P3) must equal the total force from the right team (P4, P5). This can be expressed mathematically as:

F1 + F2 + F3 = F4 + F5

Substituting the Forces

Substituting the expressions for the forces, we get:

F1/x + F2/(x - 1) + F3/(x - 2) = F4/(x - 3) + F5/(x - 4)

Finding the Distance x

This equation can be quite complex depending on the values of F1, F2, F3, F4, and F5. However, if we assume that all forces are equal (let's say F1 = F2 = F3 = F4 = F5 = F), the equation simplifies significantly:

F/x + F/(x - 1) + F/(x - 2) = F/(x - 3) + F/(x - 4)

We can cancel out F from both sides, leading to:

1/x + 1/(x - 1) + 1/(x - 2) = 1/(x - 3) + 1/(x - 4)

Solving the Equation

This equation can be solved for x using algebraic methods or numerical techniques, depending on the complexity. You can find a common denominator and simplify the equation to isolate x. This will give you the position where the object should be placed to maintain equilibrium.

Example Calculation

For instance, if we assume all forces are equal to 1 unit (F1 = F2 = F3 = F4 = F5 = 1), you would set up the equation:

1/x + 1/(x - 1) + 1/(x - 2) = 1/(x - 3) + 1/(x - 4)

By finding a common denominator and solving for x, you can determine the exact distance from P1.

In summary, the key to solving this problem is to set up the forces correctly and ensure that the left and right teams exert equal force on the object. This approach will lead you to the distance at which the object should be placed for equilibrium.